#include <stdio.h>

#include "mozilla/NullPtr.h"

#include "nsMBCSGroupProber.h"
#include "nsUniversalDetector.h"

#if defined(DEBUG_chardet) || defined(DEBUG_jgmyers)
const char *ProberName[] = {
  "UTF8",
  "SJIS",
  "EUCJP",
  "GB18030",
  "EUCKR",
  "Big5",
  "EUCTW",
};

#endif

nsMBCSGroupProber::nsMBCSGroupProber( uint32_t aLanguageFilter ) {
  for( uint32_t i = 0; i < NUM_OF_PROBERS; i++ ) {
    mProbers[i] = nullptr;
  }
  mProbers[0] = new nsUTF8Prober();
  if( aLanguageFilter & NS_FILTER_CHINESE_SIMPLIFIED ) {
    mProbers[3] = new nsGB18030Prober( aLanguageFilter == NS_FILTER_CHINESE_SIMPLIFIED );
  }
  Reset();
}

nsMBCSGroupProber::~nsMBCSGroupProber() {
  for( uint32_t i = 0; i < NUM_OF_PROBERS; i++ ) {
    delete mProbers[i];
  }
}

const char* nsMBCSGroupProber::GetCharSetName() {
  if( mBestGuess == -1 ) {
    GetConfidence();
    if( mBestGuess == -1 ) {
      mBestGuess = 0;
    }
  }
  return mProbers[mBestGuess]->GetCharSetName();
}

void  nsMBCSGroupProber::Reset( void ) {
  mActiveNum = 0;
  for( uint32_t i = 0; i < NUM_OF_PROBERS; i++ ) {
    if( mProbers[i] ) {
      mProbers[i]->Reset();
      mIsActive[i] = true;
      ++mActiveNum;
    } else
    { mIsActive[i] = false; }
  }
  mBestGuess = -1;
  mState = eDetecting;
  mKeepNext = 0;
}

nsProbingState nsMBCSGroupProber::HandleData( const char* aBuf, uint32_t aLen ) {
  nsProbingState st;
  uint32_t start = 0;
  uint32_t keepNext = mKeepNext;
  for( uint32_t pos = 0; pos < aLen; ++pos ) {
    if( aBuf[pos] & 0x80 ) {
      if( !keepNext ) {
        start = pos;
      }
      keepNext = 2;
    } else if( keepNext ) {
      if( --keepNext == 0 ) {
        for( uint32_t i = 0; i < NUM_OF_PROBERS; i++ ) {
          if( !mIsActive[i] ) {
            continue;
          }
          st = mProbers[i]->HandleData( aBuf + start, pos + 1 - start );
          if( st == eFoundIt ) {
            mBestGuess = i;
            mState = eFoundIt;
            return mState;
          }
        }
      }
    }
  }
  if( keepNext ) {
    for( uint32_t i = 0; i < NUM_OF_PROBERS; i++ ) {
      if( !mIsActive[i] ) {
        continue;
      }
      st = mProbers[i]->HandleData( aBuf + start, aLen - start );
      if( st == eFoundIt ) {
        mBestGuess = i;
        mState = eFoundIt;
        return mState;
      }
    }
  }
  mKeepNext = keepNext;
  return mState;
}

float nsMBCSGroupProber::GetConfidence( void ) {
  uint32_t i;
  float bestConf = 0.0, cf;
  switch( mState ) {
    case eFoundIt:
      return ( float )0.99;
    case eNotMe:
      return ( float )0.01;
    default:
      for( i = 0; i < NUM_OF_PROBERS; i++ ) {
        if( !mIsActive[i] ) {
          continue;
        }
        cf = mProbers[i]->GetConfidence();
        if( bestConf < cf ) {
          bestConf = cf;
          mBestGuess = i;
        }
      }
  }
  return bestConf;
}

#ifdef DEBUG_chardet
void nsMBCSGroupProber::DumpStatus() {
  uint32_t i;
  float cf;
  GetConfidence();
  for( i = 0; i < NUM_OF_PROBERS; i++ ) {
    if( !mIsActive[i] ) {
      printf( "  MBCS inactive: [%s] (confidence is too low).\r\n", ProberName[i] );
    } else {
      cf = mProbers[i]->GetConfidence();
      printf( "  MBCS %1.3f: [%s]\r\n", cf, ProberName[i] );
    }
  }
}
#endif

#ifdef DEBUG_jgmyers
void nsMBCSGroupProber::GetDetectorState( nsUniversalDetector::DetectorState( &states )[nsUniversalDetector::NumDetectors], uint32_t &offset ) {
  for( uint32_t i = 0; i < NUM_OF_PROBERS; ++i ) {
    states[offset].name = ProberName[i];
    states[offset].isActive = mIsActive[i];
    states[offset].confidence = mIsActive[i] ? mProbers[i]->GetConfidence() : 0.0;
    ++offset;
  }
}
#endif
